That is actually quite a good question.

I certainly dont think the gear is getting slower, but I am not sure that the
best gear from 10-12 years ago was significantly slower either as far as all out speeds on big days are concerned. I am sure the general level of all around speed of the newer gear has got noticeably faster though.

I think I lot of people have commented that they have not had the winds and conditions in the last few years thay they experienced before that. This is very true in some key places.
For instance, Pimbee and Lake Budgiewoi have not been at their best for weed and flat water for the last few years, and the weather patterns have not produced as meany epic days accoring to all the reports I hear.
Sandy Point has not produced many great speed days in the last few years either. It is Parlty due to the sand dune build up, but mostly due to a change in the frontal patterns we have had. There have certainly been a lot less Epic WSW days in the prime times of the year (Autumn and Spring). I think this is related to climate change which has led to a different local pattern, but it is also probably related to a periodic cyclic weather shift as well. (La Nina/El Nino etc)
Lake George has also been affected the last few years. Partly due to less than ideal water levels and weed growth, but there is no denying that the last few January to March periods didn't bring as many srong wind ESE days as we experienced in the 2012-2013 seasons.
Have you noticed different patterns in other parts of Australia?